1. Field of the Invention
The present invention relates to a spring copper alloy for electric and electronic parts having a high modulus of elasticity, a good electrical conductivity, a good spring limit value and a good solderability, and which can be produced in an inexpensive manner.
2. Related Art Statement
Heretofore, as a spring copper alloy for electric and electronic parts, there has been well-known a phosphor bronze such as JIS C-5191 alloy (5.5.about.7.0% by weight of Sn, 0.03.about.0.35% by weight of P and the remainder of Cu) and JIS C-5210 alloy (7.0.about.9.0% by weight of Sn, 0.03.about.0.35% by weight of P and the remainder of Cu).
However, the spring copper alloys mentioned above cannot satisfy the high modulus of elasticity and the good electrical conductivity now required for miniaturized electric and electronic devices operative at high frequencies. Moreover, since a 5.about.8% by weight of Sn content results an intermetallic growth when heated at 100.degree..about.150.degree. C. soldering, solderability is lessened. Also, a large increase in Sn content causes a high material cost.